i have made a few, i watched tony swanton give a demo, profile the blade in a vee shape then put the the alternating part circle profiles in with the same diameter wheel. i use a 5" then work the blade point down on the bottom of that same contact wheel untit your get the approate angle in that section and work all four angles until its right. DAMM! you have brought back how much fun it was to make those! i used old files. hope this helps
IIRC Tai ?, can't recall what the last name is showed how to forge a Keris Blade on the Neotribal forum.
I bet Tim Lively can answer your queston though.
Tim is also a Neotribalist and makes some beautiful knives. Tim posts here now and then.
Indin word for lousy hunter.